This is an optional XRAY 46 Tooth XB8 Active Differential, and includes all the necessary parts to assemble one complete Active Differential, minus diff fluid.

The unique XRAY Active Differential is a high-performance, adjustable front gear differential for XB8 buggies… vastly improving the buggy’s speed and handling characteristics. The special design of the internal components using different angled segments allows the diff gears to engage on-power to increase the forward traction and stability of the buggy, making it faster and easier to drive.

While the XRAY Active Differential is a performance option for serious racers who want to gain an edge on superior speed and handling, it is also of great benefit to drivers of all levels that want a more predictable and easy-to-drive car in all racing conditions.